• How to fall in love without losing yourself.
• How you feel about having kids.
• How to quit a job, break up with a man and confront a friend without ruining the friendship.
• When to try harder and when to walk away.
• How to kiss in a way that communicates perfectly what you would and wouldn’t like to happen next.
• The names of: the secretary of state, your great-grandmother and the best tailor in town.
• How to live alone, even if you don’t like to.
• How to take control of your own birthday.
• That you can’t change the length of your calves, the width of your hips or the nature of your parents.
• That your childhood may not have been perfect, but it’s over.
• What you would and wouldn’t do for money or love.
• That nobody gets away with smoking, drinking, doing drugs or not flossing for very long.
• Who you can trust, who you can’t and why you shouldn’t take it personally.
• Not to apologize for something that isn’t your fault.
• Why they say life begins at 30.

This is from LittleMiss[http://littlemiss.tumblr.com/post/66654561/by-30-you-should-know]